18739107817 has 2 divisors, whose sum is σ = 18739107818. Its totient is φ = 18739107816.

The previous prime is 18739107809. The next prime is 18739107853. The reversal of 18739107817 is 71870193781.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17560490256 + 1178617561 = 132516^2 + 34331^2 .

It is a cyclic number.

It is not a de Polignac number, because 18739107817 - 2³ = 18739107809 is a prime.

It is not a weakly prime, because it can be changed into another prime (18739102817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9369553908 + 9369553909.

It is an arithmetic number, because the mean of its divisors is an integer number (9369553909).

Almost surely, 2^18739107817 is an apocalyptic number.

It is an amenable number.

18739107817 is a deficient number, since it is larger than the sum of its proper divisors (1).

18739107817 is an equidigital number, since it uses as much as digits as its factorization.

18739107817 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 592704, while the sum is 52.

The spelling of 18739107817 in words is "eighteen billion, seven hundred thirty-nine million, one hundred seven thousand, eight hundred seventeen".